Hethod of and apparatus for cracking hydrocarbons



F. PUENING.

METHOD 0F AND APPARATUS FOR CRACKING HYDROCARBONS.

APPLICATION FLED SEPT 8 |921.

Reissued Nov. 29, 1921.

2 SHEETS-SHEET 1.

. wil zot SSS@ Q MN F. PUENING.

METHOD 0F AND APPARATUS FOR CRACKING HYDROCARBONS. APPLICATION mep sEP?.8.192x.

Reissued Nov. 29, 1921.

CLEdAfl/YG MII/01 HEHDEJ? aromas mmf Inventar- UNITED STATES l FRANZ PUENING, F PITTSBURGH, PENNSYLVANIA.

i METHOD OF YLAND .APPARATUS FOR CRACKI\NG HYDROCARBONS.

Specification of Reissued Letters Patent. Reissued NOV, 29, 1921.

` Original .'llo. 1,358,17"4, dated November 9, 1920, Serial No. 188,142, led December 21, 1916. ApplicationV for reissue nled September 8, 1921.

- To all whom it may-` Concern:

Be it known that I, FRANZ PUE'NING, a citizen of Germany, residing in Pittsburgh, county of Allegheny, and State of Penns l- Vania, have invented certain new and use ul Improvements in Methods of and Ap aratus for Cracking Hydrocarbons, of which the v p following is a specification.

' iin' My invention relates to a novel method of and apparatus for cracking petroleum and tars.

The modern practice in the production of asolene tends toward economy in al1 l ranches lof the art, and to this end the reliners have considered it desirable to increase the size of the stills or retorts and to distil under higher pressures and temperatures. But these conditions make it impossible to keep the stills in operation more than short periods, with long interru tions, and have increased the hazard to li e and property; and an object of the present invention is materially to lengthen the operating period and the productive capacity of the stills, to lessen the hazard of a possible blow-out by lessenin and subdividm materia stored in the still and under the direct action of the heat, and to increase the` efliciency ofthe distl'llingl units.

When cracking a certain percentage of the oill decomposes into carbon and hydrogen, which percentage increases rapidly with higher tem ratures and pressures, the carbon precipitatin onl the nearest available surface, prefera ly horizontal ones. The deposition of carbon is the greatest foe of the distiller; it acts as an insulator, checking the transmission of heat into the liquid and consequently raising the temperature of the shell. In view of the fact that the distillation is done under pressure, the likelihood of failure of the shell is great. Furthermore, as the still must be cooled down frequently to remove carbon, other strains, due

to expansion and contraction, are added,

particularly affecting the seams. The larger the stills, the greater isthe strain and danger. The new still, however, can be built in any desired size, without increasing the strain or the amount of oil liable to loss in. case of a blow-out. To make thisy possible a new method of circulating the oil in the still was devised, whichis as follows: l

The heating of hydrocarbons to the crackthe quantity of Serial No. 499,352.

ing stage results in the formation of a multitude of gas bubbles, which, due to their light weight, have a tendency to rise rapidly to the surface of the bod)T of the liquid. The formationof these bubbles also results in the lessening of the weight of a givenv body of the liquid and enables'the utilization of the thermo-siphonic principle and also the principle of the air-lift pump to eii'ect rapid circulation.v The higher speed of circulation results in greater productive capacity;

paratus, exemplications of which are shown and in which a plurality of long, vertically disposed tubes or cylinders of nelatively small cross-sectional area are connected to a header or communicating container at their upper ends, heat being applied only to the vertical walls of the cylinders. Associated with eachtube or still is an axially disposed pipe which terminates short of the lower end of the still and is of such diameter as to leave only a relatively smallspace between it and the vertical walls of the still. The upper end of the axially disposed pipe is connected to an adiacent body of liquid from which the gas bubbles have been released.'

When heat is applied to thejwalls of the 35 stills, intermediate their ends, the iiquid between the walls of the inner and* outer pipes is causedto rise rapidly to the top under the air-lift pump principle and thermo-siphonic action and-to be replaced by liquid supplied through the central pipe.

Veryrapid distillation follows the use of such apparatus for the reason that a thin lbody of liquidv is constantly under the action of a relatively high'heat, the liquid being 95 caused tocirculate by the action of the heat. itself. Thus overheating is less-likely to f occur; this for the reason that the'speed: of circulation is a function of the heat applied.

struction is that the units can move independently,no liquid in onevstill can getlost when litsfiieighbor.still blows out; that no other means, 'such as pr'OteCtingjacketS, are

necessary te avoid local superheating'ofthe 10154 retorts; that the still has no heating surfaces on which there is a downwardly flowing current; nor-is there a direct heating action The important advantage of such conf Voperating the same.

on any quiet or horizontal surface. The carbon deposits on the heating surfaces are reduced to a minimum, first, for the reason that carbon does not readil deposit on vertical surfaces, and, "secon because of the scouring `action of the rapidly circulating body of li uid.

' Ay still urther advantage in the use of such apparatus is 4that steam or gas may be supplied to the bottom of4 the still 1n the space between the two tubes with the assurance of thorough contact with every particle of the liquid under the action of theheat and at the exact point where readjustment of the atoms takes place. Furthermore, the speed of circulation may be increased or lessened by controlling the force and amount of asadmitted." i, f urther advantages will be pointed out hereinafter in .connection with the specific description of the apparatus and method of The apparatus and method ofoperating the. same. will be better understood in con' nection with the accompanying drawings, in which: y y Figure 1 is a sectional view, diagrammatic i in character, of a form of apparatus suitable for carrying out my invention; Fig. 2 is a sectional viewon of Fig. l;

Fig. 3 is a sectionalview on the line 3---3 ,i of F1g."`1;y

Fig. 4 is a view similar Vto Fig.' 1, showing a slightly modified form ofthe apparatus; Fig. 5 is an enlarged sectional view of a v fragmentary portion of the apparatus shown il1Fig.4;and

Fig. 6 is an enlarged vertical sectional View showingan addition to the apparatus illustrated in the preceding figures.

l Referring more particularly to Fig. f1, it`

Y will be seen that a hearth 10; is provided, on

whichv yfuel is placed for combustion. ,The heated gases are ycaused to flow upwardly and over the baille 11, escaping throughthe stack-lille 12.v In a suitable setting are mounted the stills or retorts `of my invention, three of such stills being shown in Fi 1. Each thereof comprises a cylindrical she l or J tube 13, relatively long and of small crossc sectional area, each of the retorts communi- 'jacent to the stills, 'and preferabl eating at its upper end with a header or container 14. The header is provided with suitable` outlets or manholes 15. The header is in open communication with a container 16, of relatively largecapacity, located adso arranged that the bulk of the liqui carried thereby is below the4 header and therefore below the open upper ends of thestills. The supplyof untreated petroleumnor tar may be obtained from a tank orcontainer indlcated` at 17, r,the material being supplied through the agency of the pump 18. Conthe line 2-2 -but extend somew As a means for causing a rapid circulation of the liquid, I provide V1n leach of the stills the axial y disposed pipes 26, the lower ends of which terminate 'ust above the lower ends of the stills, and t e upper ends of which connect with a header pipe 27. This pipe extends horizontally `through the header 14 and terminates in a T 28, the open lower end fof which is in the lower portion of the circu-r lation tank 16. The heat is caused to imgmge upon vertical surfaces only; and caron is least disposed to deposit on such surfaces. The application of heat to the liquid in this manner causesthe cracking and genasses into a condenser 21 the condensed lpper end Y h 1 ep leg1 eration of the lighter hydrocarbons, which,

in a multitude of bubbles, rise rapidly to the s urface. Following the'principle of the airl1ft pump, the li uid is ,also caused to rise rapidly and to raw in a. .corresponding vo ume of liquidfrom which the gas has been expelled but which should again pass over the heating surfaces. The rising column gives off its gas, which passes over a relatively large surface of liquid in' its passage toward the condenser. After the liquid is freed of the gas it `is withdrawn from its location and supplied to the lower ends of the stills.` A constantcirculation is therefore effected. supplied either constantly orl at? intervals through the agency of thepump, the residue remainin in the stills and circulating tank until suc time as the carbon deposit in the stills becomes too great, whereupon the apparatus is drained and the carbon cleaned.

In the apparatus shown in Figs. 4: and k5,

Untreated liquid is arrangement is made for continuous opera- `condenser connection 32 is made, the header being divided into a plurality of sections .by means of partitions 33. `These partitions do not close oil the upper portion of the header,

at above the normal liquid line fin the header, this line being indicated rising column of heated li uid simultaf neously drawing in a quantity of liquid from the adjacent section. A disadvantage in a construction such as this is in that the last stills receive only liquid which is practically spent and that the carbon deposit is likely to be much greater in those stills. Preferably the entire body of liquid is circulated as described in connection with the apparatus at Fig. 1, in ordervthat the carbon deposited may be equalized.

In the construction shown in Fig. 6 the header 39, still 40, and circulation pipe 41 may be the same as described in connection with either of the two preceding forms. In addition, however, I have entered a small ipe 42 through the vertical pipe', terminating the small pipe underneath a notched apron 43 at the lower end. Steam or a j suitable gas may be supplied through the small pipe and caused to combine with the current of liquid under the action of the heat. This may be lpractised either for the purpose of modifying the formation of new hydrocarbon combinations, or for the purpose of increasing the speed of circulation.

' At any rate, the gas is supplied at the exact point needed.

By reason of the use of apparatus such as described, it will be seen that the heat is directly applied only to vertical surfaces and that the bulk of the carbon will be kept in suspension until it settles in the container 16, where the speed of the liquid is very small, or at the lower end of each still, out

of direct contactv with the heat, or it may leave through pipe 38: that the different still units are of relatively small capacity, while providing for constant rapid circulation, yet the total volume of liquid which may escape -in the event of a blow-out, is relatively Small; that the still units, being supported in the manner described, by their contraction yandexpansion cannot throw any strain into the system. Therefore apparatus with a practically unlimited number of retorts can be built: it is apparent that the stills may be readily freed of their carbon deposits when occasion requires :I that there is no necessity for regular feeding, as the circulation is independent of the amount of oil fed in and as no danger follows a not too great variation of the level. There is jacket around the stills, reducing/"their capacity; there are no heating surfaces on which the liquid flows downwardly. Worn out retorts can be replaced easily. l

The apparatus and process described are of course typical only. The dimensions and arrangement are not essential, and modifications may be made both in the method and apparatus without departure from the spirit of my invention.

The apparatus and process may also be used for treating substn/cbs which involve similar difficulties in their treatment, the in'- vention being especially useful for the treatment of coal tar, or other such materials as contain much free carbon.

I claim:

1. In apparatus of the character described,

the combination of a vertically disposed still and means for maintaining a body of incompletely cracked liquid at a point adjacent to such still, a conduit connecting said body of liquid to the lower end of said still, the space between the walls ofthe still and the exterior of such conduit being relatively small, and means for supplying a gas or vapor to the bottom of the conduit in order to accentuate circulation, or decomposition, substantially as described.

42. The method of cracking petroleum, which consists in separating the bubbles from each stillin an individual space adjacent that still, and forcibly directing substantially all the densified liquid from said space into the circulating pipe of the next 100 still, penetrating the annular ring of that still, thereby creating, a current of liquid through all the stills in succession, substantially as described.

3. The method of treating petroleum, 105 which consists in subjecting an annular column thereof to a cracking heat, and thereby causing a rapid circulation thereof and supplying a modifying gas to a lower ortion of the column, substantially as descri ed.

4. The method o-f treating petroleum, which consists in maintaining a vertical, annular column of liquid, applying a cracking- Aheat to the sides of the column, renewing the liquid by delivering other liquid downwardly in the center of the column and supplying a Huid at a point near the lower end of the column whereby the entire body of liquid under treatment is brought in Contact with the fluid, substantially as described.

5. In means for cracking petroleum, the combination of a cylindrical vertical boiler freely suspended within a space to be heated, the heat being directly applied only at points intermediate the ends of the boiler, the space 125 at the top .of the oiler being of increased size whereby a body of liquid may be maintained, and a circulation pipe axially located in Asaid boiler, the upper end of the pipe be- 65 no necessity for placing an air or steam 'Jing laterally bent and* caused to terminate 130 kin said enlarged space at a point removed from the'u per vend of the cylindrical ortion of the iioiler, substantially as descri ed.

6. In means for cracking petroleum, the combination of a header containing a body of liquid, a lurality of vertical cylinders freely suspen ed from said header, means for directly applying heat to an intermediate ortion only of said cylinders, a centrally ibcated circulation pipe in each of said cylinders, the entrance end of said circulation pi e terminating at one side of the rising collumn of liquid from said cylinder, whereby the liquid suipplied `to the circulation pipe is withdrawn. rom a quiet porton of the `body of liquid, Substantially as described.

n 7. In means for cracking petroleum', the combination of a plurality of relatively large vertical c linders, a header within which the upper en s of thecylinders terminate, a fur. nace within which the cylinders are fneel suspended, the parts being arranged in suchY f manner that heat is directly applied only to vertical surfaces, a circulation pipe in each cylinder, the entrance end of the circulation pipe being so located as to withdraw liquid from apoint removed from the upper end of the c linders, substantially as described.

8. in a petroleum still, the combination of a header, a plurality of cylinders depending from said header, means for directly supplying heat to the intermediate vertical portions only ofjy said cylinders,and means for supplying the liquid for circulation in said cylinders by delivering the same downwardly through the axis of said cylinders, the liquid delivered downwardly bein withdrawn from an adjacent body of quiet liquid at a point removed from'the point of violent agitation, substantially as described.

9. `In means for cracking4 petroleum, the combination of a header and a plurality of relatively large, vertical stills, means for freely suspending Said stills within a heated area, the lower ends of the stills being protected from high heat, lan adjacent container for a large amount of liquid, and a circulation pipe located Within each of said stills and connected through theheader with said container, whereby the `liquid iswithdrawn from the container and delivered to the lower end of the stills without material heat-loss andwithout .being brought into contact with a directly heated surface, substantially as described.

10. In means for cracking petroleum, the combination of a header, a i vertical 'still freelyy depending therefrom, an adjacent lbulk container, and a circulation` p-ipe in said still, said pipe terminating in said container, said still and` container` being connected only at their upper ends whereby the parts may freely expand and contract without strain, substantially as described.

11. The method of cracking petroleum,

which consists in maintaining a vertical annular column-fof`liquidsupplying a cracking heat to the sides of the column thereby.

causing a rapid upward movement of the column, maintaining a separate bod of liquid at a point removed from said rising co umn, withdrawing liquid from said sepaf rate body and delivering same downwardly through the center of said. column to the lower end thereof and leading fresh liquid intothe center of said column, substantially as described.

12. In means for cracking petroleum, the

combination of a plurality of connected stills, circulation pipes in said stills for effecting rapid circulation of the body of liquid in each still, means for supplying' 4 fresh liquid to the circulation pipe` of the rst still, means for forcibly dlrecting the residue from the first still into the circulation pipe of .the next still and finally removing the spent residue from the apparatus, whereby all the liquid which enters the stills is forced to cass successively through all of the stills be ore leaving the apparatus, substantially as described.

13. Means for cracking petroleum, comprising in combination a plurality of freely depending stills of relatively large size, means` for providing an enlarged liquid containing space at theupper end of each still, a circulation pipe in each still, said pipes communicating with and being adapted to draw liquid from the space at the top of another still, substantially as described.

14. -In means for cracking petroleum, the combination of a header, a plurality ofy stills freely depending, therefrom, partition walls in said header whereby a space is provided at the top of each still, a circulation pipe end of another still, substantially as de scribed. j 15. The method of cracking petroleum, which consists in separating the bubbles from each still in an individual space adjacent that still, and forcibly 'directing substantially all the densified ,liquidI from said space into the circulating pipe of another' still, penetrating the annular ring of Inai terial in the last named still, thereby creating a'current of liquid through all the stills in succession, substantially as described.

16. The method of cracking hydrocarbons, which consists in separating4 the bubbles from `each still in an individual space adjacent that still.,and forcibly directing substantially all the densified liquid from said space into the circulating pipe of the next still, penetrating the annular ring of that still, thereby creating a current of liquid through all the stills in succession, substantially as described.

rectly supplying heat to the intermediate 17. The method of treating hydrocarbons, which consists in subjecting an annular column thereof to a cracking heat, and thereby causing -a rapid circulation thereof and supplying a modifying gas to a lower portion of the column, substantially as described.

18. The method of treating hydrocarbons, which consists in maintaining a vertical, annular column of liquid, applying a cracking heat to the sides of the column, renewing the liquid by delivering other liquid downwardly in the center of the column and supplying a fluid at a point near the lower end of the column whereby the entire body of liquid under treatment is brought in contact with the fluid, substantially as described.-

19. In -means for cracking hydrocarbons, the combination of a cylindrical vertical boiler freely suspended within a space to be heated, the heat being directly applied only at points intermediate the ends of the boiler, the space at the top of the boiler being of increased size whereby a body of liquid may be maintained, and a circulation pipe axially located in said boiler, the upper end of the pipe being laterally bent and caused to terminate in said enlarged space at a point removed from the upper end of the cylindrical A portion of the boiler, substantially as described. l

20. In means for cracking hydrocarbons, the combination of a header containing a body of liquid, a plurality of vertical cylinders freely suspended from said header, means for directly applying heat to an intermediate portion only of said cylinders, a centrally located circulation pi e in each of said cylinders, the entrance en of said circulation ipe terminating at one side of the rising co umn of liquid from said cylinder, whereby the li uid supplied to the circulation pipe is wit drawn from a quiet portion of the body of liquid, substantially as described. v

21. In means for cracking hydrocarbons,

the combination of aplurality of relatively large vertical cylinders, a header within which the upper ends of the cylinders terminate, a furnace within which the cylinders are freely suspended, the parts being arranged in such manner that the heat is 'directly applied only to vertical surfaces, a circulation pipe in each cylinder, the entrance end of the circulation pipe being so located as to withdraw liquid `from a point removed from the upper end of the cylinders, substantially as described. t

22. In a hydrocarbon still, the combination of a. header, a plurality of cylinders depending from said header, means for divertical portions only of said c linders, and means for supplying the liqui for circulation in said cylinders by delivering the same downwardly through the axis of said cylinders, the liquid delivered downwardly being withdrawn from an adjacent body of quiet liquid at a point removed from thev point of violent agitation, substantially as described; l

23. In means for cracking hydrocarbons, the combination of a header and a plurality of relatively large, vertical stills, means for freely suspending said stills within a heated area, the lower ends of the stills being Pro1 tected from high heat, an adjacent container for a large amount of liquid and a circulation pipe located within each of said stills and connected through the header with said container, whereby the liquid is withdrawn from the container and delivered to the lower end of the stills without material heat loss and without being brought into contact with a directly heated surface, substantially as described.

24. In means for cracking hydrocarbons,

the combination of a header, a vertical still freely depending therefrom, an adjacent bulk container, and a circulation pipe in said still, vsaid pipe terminating in said container, said still and container being connected only at their upper ends whereby the parts may freely expand and contract without strain, substantially as described.

25. The method of cracking hydrocarbons, which consists in maintaining a vertical annular column of liquid, supplying a cracking heat to. the sides of the column thereby causing a rapid upward movement of the column, maintaining a separate body of liquid at a point removed from said rising column, withdrawing liquid from said separate body and delivering same downwardly through the center of said column to the lower end thereof and leading fresh liquid into the center of said column, substantially as described.

26. In means for cracking hydrocarbons, the combination of a plurality of connected stills, circulation pipes in said stills for effecting rapid circulation of the body of liquid in each still, means for supplying fresh liquid to the circulation pipe of the first still, means for forcibly directing the residue from the first still into the circulation pipe of the next still and finally removing the spent residue from the apparatus, whereby all the liquid which enters the stills is forced to pass successively through all the stills before leaving the apparatus, substantially as described.

27. Means for cracking hydrocarbons, comprising in combination a plurality of freely depending stills of relativelyrlarge size, means for providing an enlarged liquid containing space at the upper end of each still, a circulation pipe in eachstill, said pipes communicating with and being adapted to draw liquid from the space at the top of another still,` substantially as described.

28. In means for crnckingl hydrocarbons,

the combination of u header, u plurulit)Y of stills freely depending therefrom, partition' walls in said header wherebyY a space is provided at the top of each still, n clrculatxon pipe in euch still, said pipe bei-ng laterallyy bent at its upper end and communicating' 10 through a partition wall with the space at the upper end of another still',y substantially as described.

29. The method of cracking hydrocsirthe bubbons, which consists in separatin .i

y ual space bles froni each still in an indivi adjacent that still, and forcibly directing" substantially :ill the densified liquid from sand space into the circulating pipe of anotlier still, penetrating the annular ring of' 

